A mitogen-activated protein kinase gene (VmPmk1) regulates virulence and cell wall degrading enzyme expression in Valsa mali. (October 2017)

• Record Type: Journal Article
• Authors: Wu, Yuxing; Xu, Liangsheng; Liu, Juan; Yin, Zhiyuan; Gao, Xiaoning; Feng, Hao; Huang, Lili
• Is Part Of: Microbial pathogenesis. Volume 111(2017)
• Page Start: 298
• Page End: 306
• Publication Date: 2017-10
• Subjects: Malus domestica -- Deletion mutant -- Conidiation -- Oxidative stress -- Immunogold; Pathogenic microorganisms -- Periodicals; Pathology, Molecular -- Periodicals; Communicable Diseases -- microbiology -- Periodicals; Communicable Diseases -- parasitology -- Periodicals; Micro-organismes pathogènes -- Périodiques; Pathologie moléculaire -- Périodiques; Electronic journals; 616.9041
• DOI: 10.1016/j.micpath.2017.09.003
• Languages: English
• ISSNs: 0882-4010

Abstract

Abstract: Mitogen-activated protein kinases (MAPKs) play critical roles in the regulation of different developmental processes and hydrolytic enzyme production in many fungal plant pathogens. In this study, an FUS3/KSS1-related MAPK gene, VmPmk1, was identified and characterized in Valsa mali, which causes a highly destructive canker disease on apple. VmPmk1 deletion mutant showed a significant reduction in growth rate in vitro, and could not produce pycnidium, indicating that the MAPK gene is important for growth and asexual development. Also, VmPmk1 played a significant role in response to oxidative stress and in the maintenance of cell wall integrity. More importantly, when deletion mutant was inoculated onto detached apple leaves and twigs, an obvious decrease in lesion size was observed. Furthermore, expression of many cell wall degrading enzyme (CWDE) genes declined in the VmPmk1 deletion mutant during infection. VmPmk1 deletion mutant also showed a significant reduction in activities of CWDEs in both induced media and infection process. Finally, the determination of immunogold labeling of pectin demonstrated that the capacity of degradation pectin was attenuated due to the deletion of VmPmk1 . These results indicated that VmPmk1 plays important roles in growth, asexual development, response to oxidative stress, and maintenance of cell wall integrity. More importantly, VmPmk1 is involved in pathogenicity of V. mali mainly by regulating CWDE genes expression. Highlights: An FUS3/KSS1 MAPK gene, VmPmk1, was characterized by gene deletion in Valsa mali. VmPmk1 was involved in growth, conidiation, response to abiotic stress, and virulence. VmPmk1 positively regulates cell wall degrading enzyme Genes Expression. Immuno gold labeling of pectin demonstrated that VmPmk1 affected pectinase activity.